Symbiotic Culture of Rice Plants with Aigamo, a Cross-Breed of Wild and Domestic Ducks
Characteristics of the Technology
This is an ecological technology for the cultivation of rice plants, based on resource recycling and positive interaction between rice plants and Aigamo, a crossbreed of wild and domestic ducks (Fig. 1). In this method, neither fertilizer nor pesticide is used. It is, therefore, low-cost and labor saving. Since it is an ecological technology, it should be adjusted to location-specific conditions such as the current system of rice cultivation, and populations of weeds and insects. Farmers are assumed to be innovative enough to adjust the technology to their own fields. This technology is recommended for rather small-scale rice farmers.
Effects of the Technology
Even though it does not use any agricultural chemical, this technology accelerates the growth of tops and roots, hence increases the yield of rice compared with routine cultivation (Table 1). This is due to the cumulative effects of the following;
- Suppression of weeds and pests, including golden snails and field rats (Fig. 2).
- Supply of quality organic fertilizers in the form of duck manure.
- Positive effects of stirring of water and topsoil, which suppresses the growth of weeds and perhaps increases the level of dissolved oxygen in the water (Fig. 3).
- The plants have frequent touch stimuli from the ducks, which perhaps produces plant hormones working in favor of plant forms resistant to lodging.
Important Notice
- After transplanted seedlings become rooted, ducklings 1-2 weeks old are introduced into the field. The reason for using ducklings is that the growth of ducklings and seedlings can be synchronized, and because Aigamo ducks are most active in catching insects at 3-5 weeks after hatching (Table 2). The optimum population of Aigamo in the field is about 200-300 birds/ha. It depends, however, on the level of available feed (weeds and insects). A lower population of Aigamo than the optimum decreases the positive effect of the birds, and a higher population both spoils seedlings and delays the growth of Aigamo. Aigamo ducks are reported to be the most suitable for this technology because of their small size (adult: 1.6 kg) and their active movement. Other indigenous small breeds of duck in Asia are also available. Aigamo ducks seldom feed on leaves of rice. However, they take ears. For this reason, the ducks should be removed from the field after the rice plants reach the heading stage. The ducks might be sold at this stage, or be kept in a pen for further growth.
- Birds are left in the field even at night, because they are more active at night than in the daytime. Hence, it is necessary to protect them from such enemies as dogs, cats, weasels and hawks. Therefore, a protective fence is indispensable. This limits the activity of the Aigamo to inside the fence. An electric fence was found to be the most effective in Japan. In case you cannot buy this in your district, you may find some other low-cost material for the fence.
- While Aigamo are in the field, water should be kept always at such a depth as to allow the birds both to swim and walk. In spots where the soil surface is above the water surface, a weeding effect cannot be expected. Water also protects birds from their enemies.
- Before introducing ducklings into the field, it is recommended to train them to get into the habit of flocking and also oiling their feathers, by leaving them in water for one or two days. It is also recommended to leave a plot of higher ground where they can rest, adjust their body temperature and oil their feathers.
Index of Images
Figure 1 Active Feeding of Aigamo
Table 1 Yield Trial of Rice in Fukuoka Prefecture, Kyushu, Japan (1999)<BR>
Figure 2 Comparison of Plant Type a: Traditional Plot B: Control Plot: A Small Area Was Enclosed by a Net to Prevent Aigamo Ducks from Entering. C: Treated Plot: Field Where Aigamo Ducks Were Kept D: Same As C Plot, except That the Treated Period Was Longer Than in C Plot<BR>
Figure 3 Population of Weeds B: Control Plot: A Small Area Was Enclosed by a Net to Prevent Aigamo Ducks from Entering. C: Treated Plot: Field Where Aigamo Ducks Were Kept
Table 2 Number of Planthoppers Observed on 15 Hills (August, 1991)<BR>
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